Preparations and processes for cleaning and disinfecting endoscopes

ABSTRACT

In the cleaning and disinfection of endoscopes, the endoscope surfaces to be cleaned are successively 
     (a) brought into contact with a cleaning solution which is heated to 55° to 65° C., kept at that temperature for 1 to 15 minutes and then drained off and which contains a low-foam nonionic surfactant, a proteolytic enzyme, at least one complexing agent and, optionally, other standard detergent constituents, and has a pH value of from 6 to 8; 
     (b) brought into contact with a disinfectant solution which is heated to 55° to 65° C., kept at that temperature for 1 to 15 minutes and then separated off and which contains an aldehyde selected from the group consisting of formaldehyde and aliphatic C 2  -C 8  dialdehydes and at least one complexing agent, and has a pH value of from 6 to 8; 
     (c) washed at least twice with water of which the pH value is adjusted to pH 6-8, the water being heated to 55° to 65° C. at least in the final wash cycle; and 
     (d) dried with sterilized hot air at 55° to 65° C., 
     water having a hardness of from 3° to 8°Gh being used in steps (a) to (c).

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to aqueous cleaning and disinfectant solutions,and to a process for cleaning and disinfecting endoscopes using suchsolutions.

2. Statement of Related Art

In medical diagnosis and therapy, surgical operations are being replacedto an increasing extent by the use of endoscopes. This development hasbeen made possible mainly by the fact that flexible glass fiberendoscopes have been available for some time. However, when used asdirected, the endoscopes become massively infected with microorganismswhich are present in body cavities, on the mucous membrane, and in theblood. Accordingly, used endoscopes have to be thoroughly cleaned anddisinfected after each use.

Glass fiber endoscopes are extremely complicated precision instrumentswhich have moving parts and whch are made from a number of materials.They are extremely difficult to clean and disinfect for a number ofreasons. Thus, not only the outer surfaces of the instrument, but alsothe narrow bores present in the interior have to be cleaned anddisinfected. In view of the sensitivity of the materials involved,cleaning and disinfection have to be performed in such a way that noresidues of the preparations used remain on the treated surfaces of theinstrument. The extremely effective process of thermal sterilizationnormally used for medical instruments cannot be applied to endoscopesbecause endoscopes are made partly of temperature-sensitive materials.Another factor to be taken into consideration is that many of the metalparts present are susceptible to corrosion. Finally, endoscopes shouldbe able to be cleaned and disinfected in a short time so that they arealways ready in good time for the treatment of the next patient. Only afew years ago were manufacturers of glass fiber endoscopes able tosucceed in developing instruments which may be completely immersed incleaning and disinfection baths and which are capable of withstandingtemperatures of up to 70° C. without damage.

DESCRIPTION OF THE INVENTION

Other than in the operating examples, or where otherwise indicated, allnumbers expressing quantities of ingredients or reaction conditions usedherein are to be understood as modified in all instances by the term"about".

An object of the present invention is to develop a process which,through a combination of thermal and chemical treatments, enablesendoscopes to be reliably cleaned and disinfected in a short time andwhich does not damage the treated instruments, even with long-termapplication. This process is also designed in such a way that it can becarried out, if desired, in an automatic washing machine. In addition,the process can be carried out in such a way that the spent cleaning anddisinfecting solutions are sterile so that they may safely be added tonormal wastewater. This object is achieved by the process describedhereinafter.

While the process of the invention has particular application toendoscopes, the process can be used to clean and sterilize othersurgical, medical, or dental devices and equipment, or in fact anyequipment or devices having hard surfaces for any use where cleaning anddisinfecting such hard surfaces is desired, particularly equipment anddevices that cannot tolerate high temperature cleaning andsterilization. For ease of expression, the process will be describedhereinafter for use with endoscopes.

The present invention relates to a process for cleaning and disinfectingendoscopes using aqueous cleaning and disinfectant solutions wherein theendoscope surfaces to be treated are successively

(a) brought into contact with a cleaning solution which is heated to 55°to 65° C., kept at that temperature for 1 to 15 minutes and then drainedoff, and which contains

at least one low-foam nonionic surfactant,

at least one proteolytic enzyme,

at least one complexing agent and

optionally other standard detergent ingredients, and has a pH value offrom 6 to 8;

(b) brought into contact with a disinfectant solution which is heated to55° to 65° C., kept at that temperature for 1 to 15 minutes and thendrained off, and which contains

at least one aldehyde selected from formaldehyde and aliphatic C₂ -C₈dialdehydes and

at least one complexing agent, and has a pH value of from 6 to 8;

(c) rinsed at least twice with water of which the pH is adjusted tobetween 6 and 8, the water being heated to 55° to 65° C. at least in thelast wash cycle; and

(d) dried with sterilized hot air at 55° to 65° C.; water having ahardness of 3° to 8° Gh (German hardness) being used in steps (a) to(c).

In step (a) the cleaning solution contains:

from 0.1 to 1.0 g/l low-foam surfactant,

from 0.03 to 0.3 AU/l proteolytic enzyme, and

from 0.03 to 0.3 g/l complexing agent

(AU=Anson Units).

Low-foam nonionic surfactants suitable for use in the cleaning solutionof step (a) are, preferably, alkylene oxide adducts of the typeobtainable by addition of from 3 to 30 moles of ethylene oxide and/orpropylene oxide with aliphatic polyols containing from 2 to 6 hydroxylgroups and from 2 to 12 carbon atoms and with fatty alcohols, fattyacids, fatty amines or alkyl phenols each containing from 8 to 18 carbonatoms (the terminal hydroxyl groups of these polyglycol etherderivatives can be etherified, esterified or acetalated). Particularlysuitable are adducts of from 3 to 15 moles of ethylene oxide withsaturated and unsaturated C₈ -C₁₈ fatty alcohols, adducts of from 3 to 5moles of ethylene oxide and from 3 to 6 moles of propylene oxide withsaturated and unsaturated C₈ -C₁₈ fatty alcohols (these mixed alkyleneoxide adducts may be prepared both by random and by blockpolymerization) and also ether derivatives of the above-described fattyalcohol alkylene glycol ethers in which the terminal hydroxyl groups areetherified with a straight-chain or branched-chain saturated aliphaticC₄ - C₈ alcohol. Preferred are polyethylene glycol ethers correspondingto the following formula:

    R.sup.1 --O--(CH.sub.2 CH.sub.2 O).sub.n --R.sup.2         (I)

in which R¹ is a straight-chain or branched-chain C₈ -C₁₈ alkyl oralkenyl radical, R² is a straight-chain or branched-chain C₄ -C₈ alkylradical and n is a number of from 7 to 12, and especially polyethyleneglycol ethers of formula I in which R¹ is a mixture of C₁₂ -C₁₈ alkyland/or alkenyl radicals emanating from a hardened or unhardened tallowfatty alcohol and R² is an n-butyl radical while n is 9 or 10.

Particularly suitable proteolytic enzymes for the cleaning solution ofstep (a) are proteases obtained from bacterial strains. Suitable enzymesare, for example, the enzymes obtained from Bacillus subtilis, Bacilluslicheniformis and Streptomyces griseus. Corresponding commercialpreparations are present either in the form of solutions of the enzymein a mixture of water and an organic solvent, for example1,2-propanediol, or as solid granulates. These commercial formsgenerally contain water-soluble calcium salts as potentiating andstabilizing agents. Solid preparations may be adjusted to a given degreeof activity by diluents, for example sodium sulfate, sodium chloride,alkali phosphate or alkali polyphosphate.

Complexing agents for use in the cleaning solution of step (a) include,for example, alkali salts of nitrilotriacetic acid, ethylenediaminetetra-acetic acid, 1-hydroxyethane-1, 1-diphosphonic acid,amino-tris-(methylenephosphonic acid), ethylenediaminetetrakis-(methylenephosphonic acid), phosphonobutane tricarboxylic acid,tartaric acid, citric acid, and gluconic acid; sodium gluconate beingparticularly preferred.

The disinfectant solution of step (b) preferably contains

from 0.5 to 5 g/l aldehyde and

from 0.02 to 0.25 g/l complexing agent.

Examples of the aliphatic C₆ -C₈ dialdehydes that can be present in thedisinfectant solution of step (b) are glyoxal, malonaldehyde,succinaldehyde, and glutaraldehyde. The disinfectant solution used instep (b) of the process of the invention preferably containsglutaraldehyde.

The disinfectant solution of step (b) may contain as complexing agentsthe same compounds which were described above as constituents of thecleaning solution of step (a). Sodium salts of phosponobutanetricarboxylic acid are preferably used in the disinfectant solution ofstep (b).

Water having a hardness of from 3° to 8° Gh is used in the process ofthe invention. This applies both to the preparation of the cleaning anddisinfectant solution and also to the wash cycles. The above degrees ofhardness are best adjusted by passing tapwater at least partly over acation exchanger which removes the cations responsible for hardness fromthe water. This cation exchange results in a displacement of the pHvalue into the alkaline range. For this reason, the pH value has to beadjusted to the indicated range of pH 6 to pH 8. The cleaning solutionand the disinfectant solution are generally prepared from concentrateswhich will be described hereinafter. These concentrates may beformulated in such a way that they give solutions having a pH value inthe required range on dilution with the tapwater treated with the cationexchanger. The water used for the wash cycles is adjusted to a pH valuein the range from pH 6 to pH 8 with physiologically safe organic acids,for example with acetic acid, tartaric acid, lactic acid, malic acid,citric acid, etc.

The spent cleaning solutions from step (a) are preferably disinfectedbefore drainage into the wastewater system. To this end, a concentrateddisinfectant solution based on formaldehyde or an aliphatic C₂ -C₈dialdehyde, and complexing agents can be added to the cleaning solutionsbefore drainage in such a quantity that, after their addition, from 0.25to 2.5 g/l of aldehyde and from 0.1 to 0.13 g/l of complexing agent arepresent in the solution as a whole.

If desired, a wash cycle can be interposed between step (a) and step(b), again being carried out with water adjusted to pH 6-8.

During their treatment with the cleaning and disinfectant solution insteps (a) and (b) of the process of the invention, the endoscopes can besimultaneously exposed to the effect of ultrasound to enhance thecleaning and disinfecting effect.

Air sterilized before heating by suction through a microfilter ispreferably used to dry the endoscopes in step (d).

The process of the invention can be carried out, for example, inclosable, heatable fine-steel containers of appropriate dimensions whichare provided with means for pumping the various liquids and the hot airused for drying through the endoscope bores to be cleaned. In addition,the containers contain inlets and outlets for the cleaning anddisinfectant solution and for the washing water and also for the hot airused to dry the instruments. It is of advantage if the endoscopes to betreated can be placed in a rack which fits in the fine steel container.To carry out the individual steps of the process of the invention, thecontainer is charged with such quantity of liquid that the endoscopesare fully immersed therein. The particular liquid present iscontinuously pumped at an adequate rate through the bores of theendoscope. When the treatment liquids are drained off, it is importantto ensure that the liquid present in the bores is also removed.

Automatic washing machines of the type known and commonly used for thecleaning of laboratory instruments and medical instruments areparticularly suitable for carrying out the process of the invention,providing they have the necessary attachments, for example means bywhich the liquids can be pumped through the bores of the endoscopes. Theouter surfaces of the endoscopes are not brought into contact with theliquids by immersion therein, but instead by continuous spraying.

The cleaning and disinfectant solutions are generally prepared fromstable, storable concentrates which, in addition to the activeingredients already described, contain further constituents of the typenormally present in such concentrates.

An aqueous detergent concentrate for preparing the cleaning solutionused in step (a) may contain, for example,

from 5 to 10% by weight low-foam nonionic surfactant,

from 7.1 to 77 AU/l proteolytic enzyme,

from 1 to 5% by weight complexing agent,

from 10 to 50% by weight enzyme stabilizer,

from 1 to 5% by weight blending aid and

from 0.05 to 0.5% by weight preservative.

The pH value of the concentrate is adjusted to pH 4-6 with acid, base oran acid-base mixture.

Suitable enzyme stabilizers for the aqueous detergent concentrate are,for example, triethanolamine, morpholine, α-pyrrolidone, ethyleneglycol, propylene glycol, glycerol, water-soluble calcium salts ormixtures of these compounds. Gylcerol and/or propylene glycol ispreferably used as the enzyme stabilizer.

Blending aids (solution promoters) suitable for the aqueous detergentconcentrate are, for example, sodium cumene solfonate, sodium toluenesulfonate, sodium xylene sulfonate, urea, polyethylene glycols, methylacetamide and fatty alcohols, such as cetyl alcohol. Sodium cumenesulfonate is preferably used as the blending aid.

The above detergent concentrates of the invention are susceptible tomicrobial infestation. Fungal growth is readily observed, particularlyin the case of preservative-free compositions. For this reason,effective quantities of preservatives are added to the concentrates.Suitable preservatives are, for example, p-hydroxybenzoic acid methylester, 5-bromo-5-nitro-1,3-dioxane, glutaraldehyde, salicylic acid,O-2-naphthyl-m-N-dimethyl thiocarbanilate,5-chloro-5-methyl-4-isothiazoline-3-one, 2-methyl-4-isothiazoline-3-oneand mixtures of the last two compounds. p-hydroxybenzoic acid methylester is preferably used as the preservative.

The observations in the foregoing description of the process of theinvention apply fully to the constituents present in the aqueousdetergent concentrate, namely the low-foam nonionic surfactant, theproteolytic enzyme and the complexing agent.

An aqueous disinfectant concentrate for preparing the disinfectantsolution used in step (b) may contain, for example,

from 10 to 40% by weight of at least one aldehyde selected fromformaldehyde and aliphatic C₂ -C₈ dialdehydes,

from 0.5 to 2% by weight of at least one complexing agent and

from 7 to 15% by weight blending aid.

The pH value of the concentrate is adjusted to pH 3-5 with acid, base oran acid-base mixture.

Particularly suitable blending aids for the disinfectant concentrate arelower aliphatic alcohols, such as ethanol, n-propanol and isopropanoland also ethylene glycol and triacetin. Ethanol is preferably used asthe blending aid.

The observations in the foregoing description of the process of theinvention again apply fully to the constituents present in the aqueousdisinfectant concentrate, namely the aliphatic dialdehyde and thecomplexing agent.

The invention is illustrated but not limited by the following example.

EXAMPLE

Concentrates were prepared by mechanically blending the followingindividual constituents (pbw=parts by weight):

Detergent concentrate

8 pbw n-butyl ether of an adduct of 9.5 moles ethylene oxide with 1 molehardened tallow fatty alcohol (formula I: R¹ =C₁₂ -C₁₈ alkyl, R² =C₄alkyl; n=9.5)

1 pbw proteolytic enzyme (Alcalase™, a product of Novo Industri A/S,Basvaerd, Denmark: 2.5 AU/g)

6 pbw glycerol

3 pbw 1,2-propylene glycol

2.5 pbw sodium gluconate

2 pbw citric acid

3 pbw sodium cumene sulfonate

0.1 pbw p-hydroxybenzoic acid methyl ester

ad 100 pbw water

The mixture was adjusted to pH 5 with 37% by weight sodium hydroxidesolution.

Disinfectant concentrate

20 pbw glutaraldehyde

1 pbw phosphonobutane tricarboxylic acid

8 pbw ethanol

ad 100 pbw water

The mixture was adjusted to pH 4 with 50% by weight sodium hydroxidesolution.

The endoscopes were cleaned and disinfected in a closable, heatablefine-steel vessel (diameter approx. 60 cm; height approx. 65 cm) whichwas provided with inlets and outlets for the cleaning and disinfectantsolution, for the water used in the wash cycles and for the hot air usedto dry the instruments. The apparatus was provided with a circulationpump by which the particular liquid present could be pumped through thebores of the fiber endoscopes.

The tests were carried out with a standard commercial gastroscope.

Water adjusted by means of a cation exchanger to a hardness of 5° Gh wasused to prepare the cleaning and disinfectant solution. The same waterwas used to carry out the wash cycles after it had been adjusted to pH 7with lactic acid.

A cleaning solution containing 0.45 g/l surfactant, 0.06 g/l enzyme and0.14 g/l sodium gluconate was prepared by dilution of the detergentconcentrate. A disinfectant solution containing 2.4 g/l glutaraldehydeand 0.12 g/l phosphonobutane tricarboxylic acid was prepared by dilutionof the disinfectant concentrate.

The air used for drying was drawn through a microfilter and, beforeintroduction into the fine steel vessel, was passed through a heatingzone in which it was heated to 60° C.

To carry out the cleaning process, the endoscope was placed in thefine-steel container in a wire basket. The bores of the endoscope wereconnected to the circulation pump. In the individual steps of theprocess, water was delivered to the fine-steel container in such aquantity that the endoscope was completely immersed. During theindividual steps of the process, the liquid present was continuouslypump-circulated through the bores of the endoscope.

After the fine-steel vessel had been filled with cleaning solution, thecleaning solution was heated to 60° C. and kept at that temperature for10 minutes. The cleaning solution ws then drained off and replaced bythe disinfectant solution which was again heated to 60° C. and kept atthat temperature for 10 minutes. After the disinfectant solution hadbeen separated off, the endoscope was washed twice with cold water. Thefine-steel vessel was then refilled with water which was heated to 60°C. and then drained off. Finally, sterile hot air was introduced for 5minutes to dry the endoscope.

In a modification of the process, disinfectant concentrate was added tothe cleaning solution of step (a) before drainage in such a quantitythat the solution as a whole contained 1.2 g/l glutaraldehyde and 0.06g/l phosphonobutane tricarboxylic acid.

To test the disinfecting effect obtained in the process of theinvention, the bores of the endoscope were contaminated with amicroorganism suspension which, in a first series of tests, contained amixture of the following microorganisms:

(1) approx. 10⁸ microorganisms/ml Staphylococcus aureus

(2) approx. 10⁸ microorganisms/ml Escherichia coli

(3) approx. 10⁸ microorganisms/ml Pseudomonas aeruginosa

(4) approx. 10⁸ microorganisms/ml Proteus mirabilis

(5) approx. 10⁸ microorganisms/ml Candida albicans

In a second series of tests, the microorganism dispersion contained only

(6) approx. 10⁸ microorganisms/ml Streptococcus faecalis.

To simulate practical conditions, the microorganism suspensionscontained an addition of 20% by weight defibrinated sheep's blood.

For contamination, the bores of the endoscope were filled with themicroorganism suspension. After brief standing, the microorganismsuspensions were drained off again. 1 hour after contamination, theendoscope was cleaned and disinfected in accordance with the invention.0.5 l of a solution containing 3% by weight Tween 80, 0.3% by weightlecithin, 0.1% by weight histidine, 0.1% by weight tryptone and 0.05% byweight sodium chloride was then drawn through the bores of theendoscope. 1 ml samples of this solution were inoculated onto agarplates which were then incubated for at least 48 hours at 37° C. or forat least 72 hours at 35° C. and subsequently tested for anymicroorganism growth present.

It was found that, where the process of the invention was applied, thenecessary freedom from microorganisms was obtained in every instance.

What is claimed is:
 1. A process for cleaning and disinfecting a deviceor equipment having hard surfaces comprising the steps of(a) contactingsuch hard surfaces with a cleaning solution at a temperature of fromabout 55° to about 65° C., maintaining such contact and such temperaturefor a period of time of from about 1 to about 15 minutes, wherein thecleaning solution containsat least one low-foam nonionic surfactant, atleast one proteolytic enzyme, at least one complexing agent, and has apH value of from 6 to 8; (b) removing the hard surfaces and the cleaningsolution from contact with each other; (c) contacting the hard surfaceswith a disinfectant solution at a temperature of from about 55° to about65° C., maintaining such contact and such temperature for a period oftime of from about 1 to about 15 minutes, wherein the disinfectantsolution containsat least one aldehyde selected from the groupconsisting of formaldehyde and aliphatic C₂ -C₈ dialdehydes, and atleast one complexing agent, and has a pH value of from 6 to 8; (d)removing the hard surfaces and the disinfectant solution from contactwith each other; (e) rinsing the hard surfaces at least twice with waterhaving a pH between about 6 and about 8 and a water temperature of fromabout 55° to about 65° C. for at least the last rinse; and (f) dryingthe rinsed hard surfaces with sterilized hot air at a temperature offrom about 55° to about 65° C.; and wherein the water used in thecleaning solution of step (a), the disinfectant solution of step (c),and the water rinses of step (e) have a German hardness value of fromabout 3° to about 8° C.
 2. The process of claim 1 wherein the device orequipment is a medical or surgical device or equipment.
 3. The processof claim 1 wherein the device or equipment is an endoscope.
 4. Theprocess of claim 1 wherein the cleaning solution in step (a)containsfrom about 0.1 to about 1.0 g/l low-foam nonionic surfactant,from about 0.03 to about 0.3 Anson Units/l proteolytic enzyme, and fromabout 0.03 to about 0.3 g/l complexing agent.
 5. The process of claim 4wherein the cleaning solution in step (a) contains as the low-foamnonionic surfactant an alkylene oxide adduct of from 3 to 30 moles ofethylene oxide and/or propylene oxide to an aliphatic polyol containingfrom 2 to 6 hydroxyl groups and from 2 to 12 carbon atoms or to a fattyalcohol, fatty acid, fatty amine, or alkyl phenol, each containing from8 to 18 carbon atoms, the terminal hydroxyl groups of these polyglycolether derivatives optionally being etherified, esterified or acetalated.6. The process of claim 5 wherein the cleaning solution in step (a)contains a low-foam nonionic surfactant which is either an adduct offrom 3 to 15 moles of ethylene oxide with saturated and unsaturated C₈-C₁₈ fatty alcohols, an adduct of from 3 to 5 moles of ethylene oxideand from 3 to 6 moles of propylene oxide with saturated and unsaturatedC₈ -C₁₈ fatty alcohols, or an ether derivative of the above fattyalcohol polyalkylene glycol ethers in which the terminal hydroxyl groupsare etherified with a straight-chain or branched, saturated aliphatic C₄-C₈ alcohol.
 7. The process of claim 1 wherein the cleaning solution instep (a) contains as the low-foam nonionic surfactant a polyethyleneglycol ether corresponding to the following formula

    R.sup.1 --O--(CH.sub.2 CH.sub.2 O).sub.n --R.sup.2         (I)

in which R¹ is a straight-chain or branched-chain C₈ -C₁₈ alkyl oralkenyl radical, R² is a straight-chain or branched-chain C₄ -C₈ alkylradical and n is a number of from 7 to
 12. 8. The process of claim 7wherein in the polyethylene glycol ether corresponding to formula I R¹is a mixture of C₁₂ -C₁₈ alkyl and/or alkenyl radicals emanating from atallow fatty alcohol, R² is an n-butyl radical, and n is a number offrom 9 to
 10. 9. The process of claim 1 wherein the cleaning solution instep (a) contains as the complexing agent at least one of an alkalimetal salt of nitrilotriacetic acid, ethylenediamine tetra-acetic acid,1-hydroxyethane-1,1-diphosphonic acid, aminotris-(methylenephosphonicacid), ethylenediamine tetrakis-(methylenephosphonic acid),phosphonobutane tricarboxylic acid, tartaric acid, citric acid, orgluconic acid.
 10. The process of claim 9 wherein the complexing agentis sodium gluconate.
 11. The process of claim 1 wherein the disinfectantsolution in step (b) containsfrom about 0.5 to about 5 g/l of at leastone aldehyde selected from the group consisting of formaldehyde andaliphatic C₂ -C₈ dialdehydes, and from about 0.02 to about 0.25 g/l ofat least one complexing agent.
 12. The process of claim 11 wherein thealiphatic C₂ -C₈ dialdehyde is glutaraldehyde.
 13. The process of claim11 wherein the disinfectant solution in step (b) contains as thecomplexing agent an alkali metal salt of one or more of nitrilotriaceticacid, ethylenediamine tetra-acetic acid,1-hydroxyethane-1,1-diphosphonic acid, aminotris-(methylenephosphonicacid), ethylenediamine tetrakis-(methylenephosphonic acid),phosphonobutane tricarboxylic acid, tartaric acid, citric acid, orgluconic acid.
 14. The process of claim 13 wherein the complexing agentis a sodium salt of phosphonobutane tricarboxylic acid.
 15. The processof claim 4 wherein the disinfectant solution in step (b) containsfromabout 0.5 to about 5 g/l of at least one aldehyde selected from thegroup consisting of formaldehyde and aliphatic C₂ -C₈ dialdehydes, andfrom about 0.02 to about 0.25 g/l of at least one complexing agent. 16.The process of claim 3 wherein the endoscope is washed at least oncewith water adjusted to pH 6-8 following step (b) and prior to step (c).17. The process of claim 1 wherein the hard surfaces are exposed toultrasound during step (a) and/or step (c).
 18. The process of claim 1wherein in step (f) the hot air is sterilized by passing it through amicrofilter.
 19. The process of claim 1 wherein the device or equipmentis a medical or surgical device at least part of which cannot toleratehigh temperature cleaning and sterilization.